Submitted to: Journal of Applied Polymer Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/23/2008
Publication Date: 2/27/2008
Citation: Cinelli, P., Chiellini, E., Imam, S.H. 2008. Hybrid composite baseed on poly(vinyl alcohol) and fillers from renewable resources. Journal of Applied Polymer Science. 109:1684-1691. Interpretive Summary: Environmentally compatible products are being developed as an alternative to petroleum-based synthetic materials, particularly, to seek suitable alternatives for conventional plastics used in the manufacturing of single-use consumer products. Materials such as renewable crops, agricultural waste and/or by-products are a good source of natural polymeric materials that are comparatively less expensive. Among them there are considerable quantities of agro-based fibers available on a worldwide basis for a variety of applications. However, the poor dimensional stability and lack of thermoplasticity of lignocellulosic fibers have limited their application in single-use products. To overcome these challenges, fibrous materials were mixed with thermoplastic polymers to produce hybrid composites of excellent property. This manuscript describes our efforts in processing of melt PVA and lignocellulosic fibers for the fabrication of hybrid composite that have good physical properties and are also susceptible to environmental biodegradation. It is expected that in the near future biodegradable polymers will replace synthetic polymers, at least in some specific applications, where a short life of the product is desirable.
Technical Abstract: Hybrid composite laminates consisting of polyvinyl alcohol (PVA) as continuous phase (33% by weight) and lignocellulosic fillers, derived from sugarcane bagasse, apple and orange waste (22% by weight) were molded in a carver press in the presence of water and glycerol such as platicizers agents. Corn starch was introduced as a biodegradation promoter and gluing component of the natural filler and synthetic polymeric matrix in the composite (22% by weight). The prepared laminates were characterized for their mechanical properties and degradative behavior in simulated soil burial experiments. The fibers type and content in composite impacted mechanical properties. Materials based on PVA and starch with apple wastes and sugarcane bagasse fillers were much harder (Young's Modulus respectively, 57, 171 MPa) than materials prepared with orange wastes (17 Mpa). Respirometric test revealed that soil microbes preferentially used natural polymers and low molecular weight additive as a carbon source compared to biodegradable synthetic polymer. The presence of PVA in formulations had no negative effect on the degradation of lignocellulosic fibers.